模仿百度首页遇到问题

为什么我的logo 放不到中间小白求解

<!DOCTYPE html>

Document
body { font: 12px arial; } a { color: black; display: inline-block; font-weight: bold; line-height: 24px; font-size: 14px; padding: 10px; } a:hover { color: #00c; } .top { float: right; margin-top: 20px; margin-right: 20px; } img { width: 270px; height: 129px; } .logo { display: block; position: relative; list-style: none; text-align: center; }